# CorrelationMDCAwareLogger.java

    /*
     * Copyright (c) 2020 WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
     *
     * WSO2 Inc. licenses this file to you under the Apache License,
     * Version 2.0 (the "License"); you may not use this file except
     * in compliance with the License.
     * You may obtain a copy of the License at
     *
     *   http://www.apache.org/licenses/LICENSE-2.0
     *
     * Unless required by applicable law or agreed to in writing,
     * software distributed under the License is distributed on an
     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
     * KIND, either express or implied.  See the License for the
     * specific language governing permissions and limitations
     * under the License.
     */
    package org.apache.synapse.commons.logger;

    import org.apache.commons.logging.Log;
    import org.apache.log4j.MDC;
    import org.apache.synapse.commons.CorrelationConstants;

    /**
     * Responsible for providing wrapper implementation for apache.commons.logging.Log interface. The logging wrapper
     * methods will put the correlation id to the MDC prior to the logging.
     */
    public class CorrelationMDCAwareLogger implements Log {

        private final Object correlationId;
        private final Log log;

        public CorrelationMDCAwareLogger(Object correlationId, Log log) {

            this.log = log;
            this.correlationId = correlationId;
        }

        @Override
        public void trace(Object o) {

            addCorrelationIdToMDC();
            log.trace(o);
        }

        @Override
        public void trace(Object o, Throwable throwable) {

            addCorrelationIdToMDC();
            log.trace(o, throwable);
        }

        @Override
        public void debug(Object o) {

            addCorrelationIdToMDC();
            log.debug(o);
        }

        @Override
        public void debug(Object o, Throwable throwable) {

            addCorrelationIdToMDC();
            log.debug(o, throwable);
        }

        @Override
        public void info(Object o) {

            addCorrelationIdToMDC();
            log.info(o);
        }

        @Override
        public void info(Object o, Throwable throwable) {

            addCorrelationIdToMDC();
            log.info(o, throwable);
        }

        @Override
        public void warn(Object o) {

            addCorrelationIdToMDC();
            log.warn(o);
        }

        @Override
        public void warn(Object o, Throwable throwable) {

            addCorrelationIdToMDC();
            log.warn(o, throwable);
        }

        @Override
        public void error(Object o) {

            addCorrelationIdToMDC();
            log.error(o);
        }

        @Override
        public void error(Object o, Throwable throwable) {

            addCorrelationIdToMDC();
            log.error(o, throwable);
        }

        @Override
        public void fatal(Object o) {

            addCorrelationIdToMDC();
            log.fatal(o);
        }

        @Override
        public void fatal(Object o, Throwable throwable) {

            addCorrelationIdToMDC();
            log.fatal(o, throwable);
        }

        @Override
        public boolean isDebugEnabled() {

            return log.isDebugEnabled();
        }

        @Override
        public boolean isErrorEnabled() {

            return log.isErrorEnabled();
        }

        @Override
        public boolean isFatalEnabled() {

            return log.isFatalEnabled();
        }

        @Override
        public boolean isInfoEnabled() {

            return log.isInfoEnabled();
        }

        @Override
        public boolean isTraceEnabled() {

            return log.isTraceEnabled();
        }

        @Override
        public boolean isWarnEnabled() {

            return log.isWarnEnabled();
        }

        private void addCorrelationIdToMDC() {

            MDC.put(CorrelationConstants.CORRELATION_MDC_PROPERTY, correlationId);
        }

    }